magnum Box - 203 205 Doubler Behind Transmission - Photo 04

The 203/205 Doubler, seen here behind a TH350 automatic, is the old standby for low gearing in fullsize trail trucks with a 1:1 high range, a 1.96 mid range, and a 3.94 low range. But although it is strong it has a few disadvantages. First is the weight; the 203 gearbox alone is 93 pounds. The length of the TH350, 203, and 205 is 44 inches (221⁄4 inches for the 203/205 alone).